Solaris

Oracle Solaris is a proprietary Unix operating system offered by Oracle for SPARC and x86-64 based workstations and servers. Originally developed by Sun Microsystems as Solaris, it superseded the company's earlier SunOS in 1993 and became known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. After the Sun acquisition by Oracle in 2010, it was renamed Oracle Solaris.

Solaris was registered as compliant with the Single UNIX Specification until April 29, 2019. Historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, and founded the OpenSolaris open-source project. Sun aimed to build a developer and user community with OpenSolaris; after the Oracle acquisition in 2010, the OpenSolaris distribution was discontinued and later Oracle discontinued providing public updates to the source code of the Solaris kernel, effectively turning Solaris version 11 back into a closed-source proprietary operating system. Following that, OpenSolaris was forked as Illumos and is alive through several Illumos distributions. In September 2017, Oracle laid off most of the Solaris teams.